Aerosol Generating Device with Environmentally Optimised Filter

ABSTRACT

An aerosol generating device includes a rod of aerosol generating material and a filter rod, and tipping paper. The filter rod includes a first filter portion and a second filter portion. The first filter portion includes acetate tow and is positioned at a mouth end of the aerosol generating device. The second filter portion is biodegradable and extends from the first filter portion to the rod of aerosol generating material. The tipping paper surrounds the filter rod and a part of the rod of aerosol generating material. The second filter portion encloses a volume which is more than 50% of a combined volume enclosed by the first and second filter portions. The tipping paper includes a line of weakening extending from the mouth end towards the rod of aerosol generating material so that at least a portion of the tipping paper can be opened, and preferably removed, by a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371of International Application No. PCT/EP2020/059003, filed Mar. 30, 2020,published in English, which claims priority to European Application No.19167618.8 filed Apr. 5, 2019, the disclosures of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a filter for an aerosol generatingdevice.

Conventional cigarettes and currently available heat-not-burn tobaccosticks comprise a tobacco containing rod, a filter, and tipping paper.Acetate tow is often chosen as a filter material as it is able toeffectively filter substances such as tar and nicotine without spoilingthe cigarette's flavour or aroma. However, it is known to be resistantto biodegradation so that acetate tow filters may take years to breakdown when disposed.

Accordingly, an object of the present invention is to accelerate thebiodegradation of filters, especially those comprising acetate as a mainconstituent, in order to reduce the environmental impact of cigarette,heat-not-burn stick, or, generally speaking, aerosol generating devicedisposal, without impacting the smoking experience of the consumer.

US 2014/224268 A1 relates to a smoking article filter. However, thefilter includes a polymer insert, which causes difficulty in terms ofpositioning and alignment during filter manufacture and the combining ofthe filter components.

In addition, the plastic insert does not promote degradability of filteras a whole after use, and thus does not reduce environmental impactsufficiently.

WO 2009/016513 A2 relates to degradable cigarette filters.

EP 2 002 737 A1 relates to a smoking article and filter. However, thesmoking article does not sufficiently improve the degradability of thefilter material. In particular, the article requires the introduction ofa thread or like in the tearing band which results in the use ofadditional material and increases the processing difficulty duringfilter manufacture, requiring registration in the tipping position orpre-processing of the whole tipping paper reels to adhere the threadsand form the weakening lines. This significantly increases the cost offilter manufacture compared to the present invention.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the invention there is provided an aerosolgenerating device comprising: a rod of aerosol generating material; afirst filter portion which comprises acetate tow and is positioned at amouth end of the aerosol generating device; a second filter portionwhich is biodegradable and is positioned between the first filterportion and the rod of aerosol generating material; and tipping papersurrounding the first filter portion and the second filter portion,wherein the tipping paper comprises a line of weakening so that at leasta portion of the tipping paper can be removed by a user.

In this way, biodegradation of a cigarette filter is acceleratedfollowing its disposal. The two-piece filter arrangement carries twosignificant advantages: the biodegradable portion accelerates filterbreak down and the acetate tow portion ensures the cigarette taste,aroma and visible filter aesthetics remain comparable to conventionalcigarettes. Moreover, the introduction of a line of weakening to thetipping paper allows the consumer to easily remove the outer materialprior to disposal of the cigarette. It has been found that tipping paperprovides a barrier to the ingress of liquid and biological elements tothe filter, which would otherwise accelerate filter degradation. Hence,by providing the consumer with the ability to remove this barrier,biodegradation can be accelerated and the environmental impact ofcigarette disposal reduced.

The second filter portion may be a paper-based material. Advantageously,paper-based filter materials, such as “Ochre”, have been found tobiodegrade at a faster rate than acetate tow. However, paper-basedmaterials often perform poorly in consumer taste tests compared withacetate tow, and exhibit an off-white colour. Therefore, a two-piecearrangement of filter elements, with the acetate tow material situatedat the visible mouth end, provides improved biodegradability withoutaffecting the filter aesthetic and only having a minimal effect onsmoking taste.

Preferably, the line of weakening in the tipping paper extends in anaxial direction with respect to the main longitudinal axis of theaerosol generating device. In this way, application of a ripping forcealong the length of the line of weakening results in a complete andefficient partitioning of the tipping paper and fully exposes theunderlying filter elements.

Typically, there are two parallel lines of lines of weakening in thetipping paper. In this way, a strip of tipping paper may be removed toallow significant ingress of liquid and biological elements to thefilter.

A tab may be formed in the tipping paper between the two parallel linesof weakening to allow the tipping paper to be gripped by a user. In thisway, the consumer is provided with a greater ease of removal of thetipping paper.

Preferably, two notches are provided in the tipping paper at the mouthend respectively adjacent the parallel lines of weakening, and whereinthe tab is provided between the notches. In this way, the tab may begripped and a ripping force applied by the consumer. The applied forceis concentrated at the notch tips thereby improving the reliability ofthe ripping process by ensuring the rips propagate along the lines ofweakening.

Preferably, the line of weakening is a line of perforations. In thisway, the line of weakening can easily be applied to the tipping paper,using a versatile procedure such as laser perforation or the use of aperforating wheel.

In one example, the aerosol generating device may be a smoking articlesuch as a tobacco rod. In other examples, the aerosol generating devicemay be a heat-not-burn stick.

According to another aspect of the invention, there is provided a methodof producing an aerosol generating device, comprising: providing a rodof aerosol generating material; providing a first filter portion, whichcomprises acetate tow, at a mouth end of the aerosol generating device;providing a second filter portion, which is biodegradable, between thefirst filter portion and the rod of aerosol generating material;providing tipping paper surrounding the first filter portion and thesecond filter portion; and applying a line of weakening to the tippingpaper so that at least a portion of the tipping paper can be removed bya user.

Preferably, the line of weakening is a line of perforations. In oneexample, the line of perforations may be created using a laser. Inanother example, the line of perforations may be created using aperforating wheel.

The line of weakening may be applied to the tipping paper after thetipping paper is attached to the aerosol generating device.Alternatively, the line of weakening may be applied to the tipping paperbefore the tipping paper is attached to the aerosol generating device.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are now described, by way of example, withreference to the drawings, in which:

FIG. 1 is a perspective view of a cigarette including an illustrativecut-away section in an embodiment of the invention;

FIG. 2 is an exploded view of the cigarette depicted in FIG. 1;

FIG. 3A is a side view of the cigarette depicted in FIG. 1;

FIG. 3B is a cross-sectional side view of the cigarette depicted in FIG.1;

FIG. 4A is a cross-sectional side view of an arrangement of cigaretteelements used in the production of a cigarette in an embodiment of theinvention; and

FIG. 4B is a side view of an arrangement of cigarette elements used inthe production of a cigarette in an embodiment of the invention.

DETAILED DESCRIPTION

FIGS. 1, 2, 3A and 3B are schematic views of a smoking article 10, inthis case a cigarette 10, in an embodiment of the invention. Thereference to a smoking article 10 shall in the context of the presentinvention and description not be construed as limited to cigarettes orother kinds of tobacco products requiring burning of tobacco material togenerate an aerosol inhaled by a user. The terms smoking article shallto the contrary apply and be construed to also encompass any kind ofaerosol generating devices making use of tobacco containing substrates,be it plain tobacco leaves, tobacco cut-filler, reconstituted tobacco ortobacco extracts in all forms, for generating an inhalable aerosolthrough any kind of heating technique. It may in particular encompassany heat-not-burn tobacco containing consumable device used inconnection with a filter for consumption by users.

The cigarette 10 comprises a smoking rod 12 connected to a filter 14.The filter 14 comprises two cylindrical filter portions: a first filterportion 16 positioned at the mouth end 15 of the filter 14 and a secondfilter portion 18 positioned between the first filter portion 16 and thesmoking rod 12.

The first filter portion 16 comprises acetate tow material and thesecond filter portion 18 comprises a biodegradable material thatdegrades at a faster rate than acetate tow. In one example, the secondfilter portion 18 may comprise the paper-based material “Ochre”, whichhas been found to degrade more rapidly than filters constructed withacetate tow. In other examples, the second filter portion 18 maycomprise any other filter material that biodegrades more rapidly thanacetate tow.

The first filter portion 16 and the second filter portion 18 eachenclose a respective volume. The second filter portion 18 constitutes,according to the invention, a larger proportion of the combined filter14 volume. The second filter portion 18 thus constitutes more than 50%of the combined filter 14 volume. Preferably at least 75% and up to 95%thereof. In a preferred embodiment the second filter portion 18 formsabout 85% of the total filter volume, the remainder (i.e. 15%) beingformed by the first filter portion 16. In this way, the second filterportion 18 provides a greater contribution to the overall degradationrate of the filter 14 than the acetate tow first filter portion 16,thereby accelerating overall degradation. However, it will beappreciated by the skilled person that the relative proportions of thetwo filter 14 portions may be configured according to specific smokingrequirements in consideration of the above-defined principles. In thisway, other filter properties such as taste, pressure drop, filtrationcharacteristics, degradation rate, and cost may be controlled byaltering the relative portions of the first filter portion 16 and thesecond filter portion 18.

By situating the acetate tow first filter portion 16 at the mouth end15, the exposed face of the filter 14 is seen to resemble that of aconventional cigarette. Therefore, consumer perception of the cigarette10 remains unaffected and a similar taste experience is provided.

The filter 14 is wrapped in tipping paper 20, wherein the tipping paper20 conforms to the shape of the underlying filter 14. The tipping paper20 comprises at least one, and preferably as represented two parallellines of perforations 22 and 23 which extend in an axial direction withrespect to the main longitudinal axial of the cigarette 10. Two notches24 and 25 are provided at the mouth end 15 of each perforation line 22and 23 and a tab 26 is formed between the notches 24 and 25.

The consumer is able to grip the tab 26 and apply a ripping force alongthe perforation lines 22 and 23 resulting in the removal of a strip oftipping paper 20 from the filter 14. In this way, following disposal ofthe cigarette 10, biodegradation of the filter 14 is accelerated as theingress of liquid and biological components to the filter 14 is nolonger blocked by the tipping paper 20.

There are many other possible perforation arrangements, as will beappreciated by the skilled person. In one example, the perforations mayextend circumferentially or helically around the filter 14, or there mayonly be one line of perforations. In another example, the notches 24 and25 and tab 26 may be positioned at the other end of the filter 14,adjacent to the smoking rod 12. In another example, the notches 24 and25 or tab 26 may be absent.

As will be appreciated by the skilled person, the lines of perforationsmay comprise any alternative form of line of weakening, wherein the lineof weakening enables the tipping paper 20 to easily be ripped by theconsumer. In one example, the line of weakening may comprise a portionof tipping paper 20 having a thickness that is thinner than the rest ofthe tipping paper 20. In another example, the line of weakening maycomprise a chemically weakened portion. In another example, the line ofweakening may comprise a radiatively weakened portion. In anotherexample, the line of weakening may comprise a mechanically weakenedportion. In another example, the line of weakening may comprise aportion of tipping paper 20 made from a weaker material than the rest ofthe tipping paper 20.

In embodiments of the invention, the lines of perforations 22, 23 extendfrom the mouth end towards the smoking rod 12 over more than 50% of thelength of the tipping paper along the longitudinal axis of the smokingarticle. Thus, a user can ensure, upon breaking of the tipping paper,that both the first and second filter portions 16, 18 get exposed to theoutside environment and consequently that water ingress is permittedinto the biodegradable second filter portion 18.

Preferably, the lines of perforations 22, 23 extend from the mouth endtowards the smoking rod 12 over the entire length of the tipping paper20, such that a user can fully open the tipping paper to release bothfilter portions 16, 18 free and fully expose it to the outsideenvironment after smoking the article 1.

The smoking rod 12 contains shredded tobacco 28. A number of otherproducts and aerosol generating ingredients may be provided within thesmoking rod 12, as will be appreciated by a person skilled in the art.

The filter 14 is wrapped in tipping paper 20 which extends beyond thelength of the filter 14. In this way, the tipping paper 20 also wrapsaround a portion of the smoking rod 12, thereby providing secureattachment of the filter 14 to the smoking rod 12. In an alternativeembodiment, the tipping paper 20 may be the same length as the filter14. In one example, the tipping paper 20 may be fed from a reel andattached to the cigarette 10 during manufacture.

The filter 14 is wrapped in plug wrap paper 30 which is provided betweenthe filter 14 and the tipping paper 20. The plug wrap paper 30 is used,as commonly known in cigarette filter making, to hold the two filterelements 16, 18 together firmly during manufacture and use, inparticular to ensure proper filter 14 integrity upon attachment to thesmoking rod 12 with the tipping paper 20. In one example, the tippingpaper 20, plug wrap paper 30, first filter portion 16 and the secondfilter portion 16 may be joined using an adhesive.

The perforations of the perforation lines 22 and 23 only penetrate thetipping paper 20, and do not extend through the plug wrap paper 30. Thisensures that filter 14 properties such as the pressure drop oninhalation and substance permeability are unaffected by the presence ofthe perforations. In this way, a comparable smoking experience to aconventional cigarette is provided to the consumer.

In alternative embodiments, the perforations may extend through the plugwrap paper 30 to enable the removal of both the tipping paper 20 and theplug wrap paper 30. This would provide an even greater level of liquidand biological ingress to the filter 14, thereby further acceleratingdegradation.

The perforation lines 22 and 23 may be created using methods such aslaser perforation, use of perforating wheel, or any other suitableperforation technique. In one example, the perforations may be createdprior to application of the tipping paper 20 to the filter 14. In analternative example, the perforations may be created after applicationof the tipping paper 20 to the filter 14.

FIGS. 4A and 4B show a side view and cross-sectional side viewrespectively of an arrangement of cigarette elements used in theproduction of a cigarette in an embodiment of the invention.

The arrangement comprises a smoking rod 12, a second filter portion 18,a first filter portion 16, another second filter portion 16, and anothersmoking rod 12 provided respectively in an abutting sequence. Tippingpaper 20 is wrapped around the arrangement and a laser, or any othersuitable tool, used to create two parallel lines of perforations 22 and23 extending in an axial direction with respect to the main longitudinalaxis of the arrangement. The laser is also used to form two notches 24and 25 in the tipping paper 20: one at the centre of each line ofperforation with respect to the main longitudinal axis of thearrangement. In alternative examples, the lines of perforations 22 and23 may be any other lines of weakening, such as a thinner portion oftipping paper 20.

A cutting device, such as a saw or laser, can be used to cut through themirror plane lying perpendicular to the longitudinal axis of thearrangement, thereby producing two cigarettes 10, each with two parallellines of perforations 22 and 23 and two notches 24 and 25 provided attheir mouth ends 15, as shown in FIGS. 1, 2, 3A and 3B.

1. An aerosol generating device comprising: a rod of aerosol generatingmaterial; a filter rod, the filter rod comprising: a first filterportion which comprises acetate tow and is positioned at a mouth end ofthe aerosol generating device; a second filter portion which isbiodegradable and which extends from the first filter portion to the rodof aerosol generating material; and tipping paper surrounding the filterrod and a part of the rod of aerosol generating material such that thefilter rod and the rod of aerosol generating material are coupledtogether along a common longitudinal axis, wherein the second filterportion encloses a volume which is more than 50% of a combined volumeenclosed by the first and second filter portions, and wherein thetipping paper comprises a line of weakening extending from the mouth endtowards the rod of aerosol generating material so that at least aportion of the tipping paper can be opened by a user.
 2. The aerosolgenerating device of claim 1, wherein the second filter portion is apaper-based material.
 3. The aerosol generating device of claim 1,wherein the line of weakening in the tipping paper extends over morethan 50% of a length of the tipping paper along the longitudinal axis.4. The aerosol generating device of claim 1, wherein the line ofweakening in the tipping paper extends along an entire length of thetipping paper along the longitudinal axis.
 5. The aerosol generatingdevice of claim 1, further comprising another line of weakening parallelto the line of weakening in the tipping paper.
 6. The aerosol generatingdevice of claim 5, wherein a tab is formed in the tipping paper betweenthe two parallel lines of weakening to allow the tipping paper to begripped by a user.
 7. The aerosol generating device of claim 6, whereintwo notches are provided in the tipping paper at the mouth endrespectively adjacent the parallel lines of weakening, and wherein thetab is provided between the notches.
 8. The aerosol generating device ofclaim 1, wherein the line of weakening is a line of perforations.
 9. Theaerosol generating device of claim 1, wherein the aerosol generatingdevice is a smoking article.
 10. A method of producing an aerosolgenerating device, comprising: providing a rod of aerosol generatingmaterial; providing a filter rod, the filter rod comprising: a firstfilter portion which comprises acetate tow and is positioned at a mouthend of the aerosol generating device; a second filter portion which isbiodegradable and which extends from the first filter portion to the rodof aerosol generating material and which encloses a volume which is morethan 50% of a combined volume enclosed by the first and second filterportions; providing tipping paper surrounding the filter rod and a partof the rod of aerosol generating material such that the filter rod andthe rod of aerosol generating material are coupled together along acommon longitudinal axis; and applying a line of weakening to thetipping paper extending from the mouth end towards the rod of aerosolgenerating material so that at least a portion of the tipping paper canbe opened, and preferably removed, by a user.
 11. The method of claim10, wherein the line of weakening is a line of perforations.
 12. Themethod of claim 11, wherein the line of perforations is created using alaser or a perforating wheel.
 13. The method of claim 10, wherein theline of weakening is applied to the tipping paper before the tippingpaper is attached to the aerosol generating device.
 14. The method ofclaim 10, wherein the line of weakening in the tipping paper extendsover more than 50% of a length of the tipping paper along thelongitudinal axis.
 15. The method of claim 10, wherein the line ofweakening in the tipping paper extends along an entire length on thetipping paper along the longitudinal axis.
 16. The method claim 10,wherein the second filter portion is a paper-based material.
 17. Themethod claim 10, wherein the step of applying the line of weakeningcomprises applying two lines of weakening extending in parallel from themouth end towards the rod of aerosol generating material.
 18. The methodaccording to claim 17, wherein two notches are provided in the tippingpaper at the mouth end respectively adjacent the parallel lines ofweakening, and wherein a tab is provided between the notches.
 19. Themethod of claim 10, wherein the line of weakening is applied to thetipping paper after the tipping paper is attached to the aerosolgenerating device.